Remove dependency on external RethinkDB instance

bigchaindb/pipelines/utils.py

@@ -29,7 +29,7 @@ class ChangeFeed(Node):
     DELETE = 2
     UPDATE = 4
 
-    def __init__(self, table, operation, prefeed=None):
+    def __init__(self, table, operation, prefeed=None, bigchain=None):
         """Create a new RethinkDB ChangeFeed.
 
         Args:
@@ -40,13 +40,14 @@ class ChangeFeed(Node):
                 (e.g. ``ChangeFeed.INSERT | ChangeFeed.UPDATE``)
             prefeed (iterable): whatever set of data you want to be published
                 first.
+            bigchain (``Bigchain``): the bigchain instance to use (can be None).
         """
 
         super().__init__(name='changefeed')
         self.prefeed = prefeed if prefeed else []
         self.table = table
         self.operation = operation
-        self.bigchain = Bigchain()
+        self.bigchain = bigchain or Bigchain()
 
     def run_forever(self):
         for element in self.prefeed:

tests/test_run_query_util.py

@@ -1,3 +1,4 @@
+from unittest.mock import patch
 from threading import Thread
 import pytest
 
@@ -26,85 +27,81 @@ def test_raise_exception_when_max_tries():
 
 def test_reconnect_when_connection_lost():
     import time
+    import rethinkdb as r
 
-    proc = None
+    def raise_exception(*args, **kwargs):
+        raise r.ReqlDriverError('mock')
+
+    conn = Connection()
+    original_connect = r.connect
+    r.connect = raise_exception
 
     def delayed_start():
-        nonlocal proc
         time.sleep(1)
-        proc, _ = start_temp_rethinkdb(38015)
+        r.connect = original_connect
 
     thread = Thread(target=delayed_start)
-    conn = Connection(port=38015)
     query = r.expr('1')
     thread.start()
     assert conn.run(query) == '1'
-    proc.terminate()
-    proc.wait()
 
 
 def test_changefeed_reconnects_when_connection_lost(monkeypatch):
-    import os
     import time
-    import tempfile
     import multiprocessing as mp
 
-    import bigchaindb
+    from bigchaindb import Bigchain
     from bigchaindb.pipelines.utils import ChangeFeed
 
-    dbport = 38015
-    dbname = 'test_' + str(os.getpid())
-    directory = tempfile.mkdtemp()
+    class MockConnection:
+        tries = 0
 
-    monkeypatch.setitem(bigchaindb.config, 'database', {
-        'host': 'localhost',
-        'port': dbport,
-        'name': dbname
-    })
+        def run(self, *args, **kwargs):
+            return self
 
-    proc, _ = start_temp_rethinkdb(dbport, directory=directory)
+        def __iter__(self):
+            return self
 
-    # prepare DB and table
-    conn = r.connect(port=dbport)
-    r.db_create(dbname).run(conn)
-    r.db(dbname).table_create('cat_facts').run(conn)
+        def __next__(self):
+            self.tries += 1
+            if self.tries == 1:
+                raise r.ReqlDriverError('mock')
+            elif self.tries == 2:
+                return { 'new_val': { 'fact': 'A group of cats is called a clowder.' },
+                         'old_val': None }
+            if self.tries == 3:
+                raise r.ReqlDriverError('mock')
+            elif self.tries == 4:
+                return { 'new_val': {'fact': 'Cats sleep 70% of their lives.' },
+                         'old_val': None }
+            else:
+                time.sleep(10)
 
-    # initialize ChangeFeed and put it in a thread
-    changefeed = ChangeFeed('cat_facts', ChangeFeed.INSERT)
+
+    bigchain = Bigchain()
+    bigchain.connection = MockConnection()
+    changefeed = ChangeFeed('cat_facts', ChangeFeed.INSERT,
+                            bigchain=bigchain)
     changefeed.outqueue = mp.Queue()
     t_changefeed = Thread(target=changefeed.run_forever, daemon=True)
 
     t_changefeed.start()
     time.sleep(1)
+    # try 1: MockConnection raises an error that will stop the
+    #        ChangeFeed instance from iterating for 1 second.
 
-    # insert some records in the table to start generating
-    # events that changefeed will put in `outqueue`
-    r.db(dbname).table('cat_facts').insert({
-        'fact': 'A group of cats is called a clowder.'
-    }).run(conn)
-
-    # the event should be in the outqueue
+    # try 2: MockConnection releases a new record. The new record
+    #        will be put in the outqueue of the ChangeFeed instance.
     fact = changefeed.outqueue.get()['fact']
     assert fact == 'A group of cats is called a clowder.'
 
-    # stop the DB process
-    proc.terminate()
-    proc.wait()
-
+    # try 3: MockConnection raises an error that will stop the
+    #        ChangeFeed instance from iterating for 1 second.
     assert t_changefeed.is_alive() is True
 
-    proc, _ = start_temp_rethinkdb(dbport, directory=directory)
-
     time.sleep(2)
-
-    conn = r.connect(port=dbport)
-    r.db(dbname).table('cat_facts').insert({
-        'fact': 'Cats sleep 70% of their lives.'
-    }).run(conn)
+    # try 4: MockConnection releases a new record. The new record
+    #        will be put in the outqueue of the ChangeFeed instance.
 
     fact = changefeed.outqueue.get()['fact']
     assert fact == 'Cats sleep 70% of their lives.'
-
-    # stop the DB process
-    proc.terminate()
-    proc.wait()